Black salt A type of rock salt composed of sodium chloride with several other components lending the salt its color and smell. Black salt has been used since ancient times and is said to have been identified by Maharishi Charak the father of Ayurvedic medicine around 300 B.C.E. There are anecdotal claims from Ayurvedic healers that this type of black salt can be therapeutic. It is considered a cooling spice and it is used as a laxative and to help digestive problems poor eyesight and hysteria. Black salt tends to have less sodium than table salt so it can be helpful to people with high blood pressure and/or on low-salt diets. It is very popular in India Middle East France Japan and Spain. Its also called as Black lava salt kala namak salt or sanchal and is a type of volcanic rock salt. Its commonly used in Asian countries surrounding the Himalayan Mountains like India and Pakistan. It has been used for hundreds of years as traditional medicine for cooking and as a beauty aid.